diff --git a/simplelabel/models.py b/simplelabel/models.py
index ff9be9e..365d2ac 100644
--- a/simplelabel/models.py
+++ b/simplelabel/models.py
@@ -54,7 +54,9 @@ def get_number_polls(self):
     get_number_polls.short_description = "Number of polls"
 
     def get_percentage_done(self):
-        return round((self.get_number_polls() / (self.dataset_max_polls * self.get_number_images()))*100.0)
+        if self.dataset_max_polls > 0 and self.get_number_images() > 0:
+            return round((self.get_number_polls() / (self.dataset_max_polls * self.get_number_images()))*100.0)
+        return 0.0
     get_percentage_done.short_description = "Percentage done"
 
     def __str__(self):